Attachment security differs by later autism spectrum disorder: A prospective study.

Although difficulties with social relationships are key to autism spectrum disorder (ASD), no previous study has examined infant attachment security prior to ASD diagnosis. We prospectively assessed attachment security at 15 months in high-risk infants with later ASD (high-risk/ASD, n = 16), high-risk infants without later ASD (high-risk/no-ASD, n = 40), and low-risk infants without later ASD (low-risk/no-ASD, n = 39) using the Strange Situation Procedure. High-risk/ASD infants were disproportionately more likely to be classified as insecure (versus secure) and more likely to be classified as insecure-resistant (versus secure or avoidant) than high-risk/no-ASD and low-risk/no-ASD infants. High-risk infants with insecure-resistant attachments were over nine times more likely to receive an ASD diagnosis than high-risk infants with secure attachments. Insecure-resistant attachment in high-risk infants suggests a propensity toward negative affect with the parent in conditions of stress. Insecure-resistant attachment may prove useful as a potential early index of propensity toward ASD diagnosis in high-risk siblings, while insecure-resistant attachment in the context of emergent autism may contribute to difficulties experienced by children with ASD and their families.